Flexible band track



4Feb. 20, 1934.` H. A. KNOX FLEXIBLE BAND TRACK Filed March 25, y1953fI-l- IN VEN TOR.

Ew A-Kwx /0 BY W A TTORNEY Patented Feb. 20, 1934 UNITED STATES PATENTOFFICE Claims.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) The invention described hereinmay be manufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

5 This invention relates to a flexible band track for track-layingvehicles.

The principal object of this invention is to provide a exible band trackin which endless bands formed of a material such as rubber are 10strengthened, supported and held in spaced relation by means oftransversely extending, rigid members constituting driving lugs andwheel guides.

To these and other ends, the invention conlll sists in the construction,arrangement and combination of elements described hereinafter andpointed out in the claims forming a part of this specication.

A practical embodiment of the invention is illustrated in theaccompanying drawing, where- 1n:

Fig. 1 is a plan view partly in section and taken on the line 1-1 ofFig. 2 of a portion of the lower flight of a track constructed inaccordance with the invention.

Fig. 2 is a detail view taken on the line 2-2 of Fig. 1.

Fig. 3 is a detail view taken on the line 3-,-3 of Fig. 2.

The track consists of two endless, laterally spaced bands 5 and 6 formedof a flexible material such as rubber. The bands are each reinforced bymeans of a plurality of endless cords or rubberized steel cables 7,disposed laterally of each band on an approximately center line.

The spaced bands 5 and 6 are rigidly interconnected by means of rigidmembers A extending transversely across the bands and spaced from eachother in the longitudinal direction of the track. The members A are allidentical and each one consists of a central semi-circular part 8constituting a driving lug, a pair of laterally spaced upstanding 4arms9-9 constituting 'guide lugs, and two sets of laterally extending,vertically spaced arms 10-10. The spaced arms 10 of each set arepositioned above and below the row of cables 7 in one of the bands, andare embedded in the band. The arms 10 on each side of the member A areconnected by a plate 11 (Fig. 3) which closes the end of thesemi-circular part 8.

The bands are resiliently interconnected by transversely extendingportions 12 underlying n the rigid members A. These portions arecomposed of the same material as the bands and are integral therewith.They extend into the semlcylindrical space of the part 8.

The outer tread portion of the track is formed to provide cleats 13extending transversely of the track and lying substantially in the traceof the rigid members A. As seen in Fig. 2, the additional height orthickness of the bands at this portion compensates for the volumetricdisplacement of the arms 10.

The arms also serve to transmit the pressure exerted by the weight ofthe vehicle in a more or less uniform manner through the entirethickness of the bands.

I claim:

1. A track for track-laying vehicles comprising laterally spaced,endless bands formed of a iiexible material such as rubber, spaced rigidmembers extending transversely of the bands, each member including acentral, semi-cyliny drical part disposed between the bands andconstituting a driving lug, a pair of laterally spaced arms extendingvertically from the central part 4and constituting guide lugs, and pairsof vertically spaced arm's extending laterally from the sides of thecentral part and embedded in the bands, transversely extending membersof the same material as the bands connecting the spaced bands andunderlying the rigid members, reinforcing cables embedded in the bandsand passing between the vertically spaced arms, and the bands having agreater thickness in the trace of the rigid members to providetransversecleats.

2. A track for track-laying vehicles comprising laterally spaced,endless bands formed of a flexible material such' as rubber, spacedrigid members extending transversely of the bands, each member includinga central, semi-cylindrical part disposed between the bands andconstituting a driving lug, and pairs of vertically spaced armsextending laterally from the sides of the central part and embedded inthe bands, transversely extending members of the same material as thebands connecting the spaced bands and underlying the rigid members,reinforcing cables embedded in the bands and passing between thevertically spaced arms.

3. A track for track-laying vehicles comprising laterally spaced endlessbands formed of a resilient material such' as rubber, spaced rigidmembers extending transversely of the bands, each member including acentral semi-cylindrical part having closed ends and disposed betweenthe bands, arms extending laterally from the closed ends of the centralpart and embedded in the bands, transversely extending members of thesame material as the bands and connecting the spaced bands, each of saidmembers underlying the central part of one of the rigid members andhaving a portion disposed within the semi-cylindrical part of the rigidmember.

4. A track for track-laying vehicles comprising laterally spacedendlessbands formed of a flexible material such as rubber, spaced rigidmembers extending transversely of the bands, each member including acentral part disposed between the bands and constituting a driving lug,a pair of laterally spaced arms extending vertically from the centralpart and constituting guide lugs, pairs of vertically spaced armsextending laterally from the central part and em-

